Impact of Fronto-Orbital Advancement on Frontal Sinus Volume, Morphology, and Disease in Nonsyndromic Craniosynostosis.

Background: Fronto-orbital advancement for nonsyndromic craniosynostosis has been thought to injure frontal sinus buds, lead to chronic sinus disease, and influence final forehead shape. This study investigates the effect of fronto-orbital advancement in infancy on subsequent frontal sinus volume, morphology, and disease.

Methods: The authors conducted a retrospective review of nonsyndromic craniosynostosis patients treated with fronto-orbital advancement in infancy with a head computed tomographic scan obtained at age 7 to 18 years. Facial trauma patients served as age-matched controls. Frontal sinus characteristics were determined using three-dimensional reconstructions.

Results: The study included 33 nonsyndromic craniosynostosis patients who underwent fronto-orbital advancement (n = 20 unicoronal; n = 13 metopic) and 20 control patients. The incidence of at least unilateral pneumatization was 94 percent for fronto-orbital advancement subjects and 95 percent for control subjects. Mean frontal sinus volumes for unicoronal synostosis, metopic synostosis, and control groups were 3427 ± 2294, 4576 ± 3510, and 4157 ± 3963 mm, respectively (p = 0.598). Asymmetry scores were as follows: unicoronal synostosis, 56 ± 35 percent; metopic synostosis, 36 ± 33 percent; and control, 23 ± 24 percent (p = 0.010). Unicoronal subjects displayed prominent asymmetry, with increased pneumatization on the unaffected side. Frontal sinus volume correlated with age at computed tomography but not with age at fronto-orbital advancement. Interrater reliability was 0.997. One fronto-orbital advancement subject and zero control subjects demonstrated computed tomographic evidence of frontal sinus disease.

Conclusions: Frontal sinus volume, morphology, and disease do not differ significantly between control subjects and nonsyndromic craniosynostosis subjects following fronto-orbital advancement, but subtle differences such as increased asymmetry in the unicoronal synostosis group can be appreciated. Further research with syndromic craniosynostosis patients undergoing multiple procedures may help elucidate the association between surgical disruption and frontal sinus development.

Clinical Question/level Of Evidence: Therapeutic, III.